"Our volunteers were trained to forget neutral information in a controlled laboratory environment. Training to forget a traumatic event would be more complex."

The study has not only shown that one can deliberately forget things, through EEG measurements, the researchers have also managed to capture the exact moment when the memory is inhibited, that is when the forgetfulness is imposed.

Waldhauser said: "The inhibition of memory eases off after a few hours. But the more often information is suppressed, the more difficult it becomes to retrieve it."

"If the memories have been suppressed over a long period of time, they could be extremely difficult to retrieve," he added.